The present invention relates to power semiconductor devices and more particularly to a termination arrangement for a superjunction power semiconductor device.
A superjunction arrangement having a cellular design in the active region thereof can be terminated with dense p-columns as a transition to a race-track structure. The weak point of the device with respect to avalanche breakdown is at the interface between the active cells and the dense p-columns in the transition region. Conventional designs utilize a transition region having a hexagonal lattice similar to the hexagonal lattice of the active cells, but with half the lattice constant and, crucially, offset. The offset breaks the symmetry in some lattice directions resulting in weak points where the device is more susceptible to avalanche breakdown.